An extended relative once pulled me aside at a holiday gathering, confused by my 4-year-old foster son’s uncharacteristic moodiness. Instead of the typically spirited, joyful little boy he’d most often been since he came to live with us eight months earlier, my foster son was sullen and withdrawn.

“What’s up with him today?” the relative asked me in a low voice.

“Oh, well, it’s Christmas,” I said. “He’s talked to his parents on the phone a couple of times, but it’s not the same as actually being with them. He’s missing his family.”

“Missing those people?” he scoffed. “Please. That kid has it made here.”

It wasn’t the first — or last — time I’d hear that somehow my foster children were lucky. Lucky to have landed in middle-class America and, in particular, with me and my husband and our son. Not only were they lucky but they should also recognize and appreciate just how lucky they were. But they knew — and I knew — that as children who had been torn from their biological families through absolutely no fault of their own, they were anything but lucky. They were not lucky to be living with uncertain futures, missing the only family they’d ever known.

The NBC drama “This Is Us” recently tackled this very concept. Its foster care story line showcases the character of an adolescent girl and her relationships with her birth mother and her upper-middle-class foster family.

“There has already been an awakening of the importance” of continued contact with the biological family “among those of us within the system,” said Patricia Bresee, a former juvenile court judge in California. “But now, with TV shows like ‘This Is Us,’ hopefully there will be more of an awakening among the public.”

Ms. Bresee, a retired California Superior Court Commissioner, now serves as vice chairwoman for the board of trustees for the national Court-Appointed Special Advocate Association, which advocates for children in foster care. She points out that the vast majority of children who are removed from their homes and placed in foster care are not removed for abuse; more often, they’re removed for neglect.

Many make the assumption “that these kids have escaped torture, but it’s the only home they’ve ever known,” she said. “Their definition of love and caring came from their own experiences.”

“This Is Us,” which concluded its second season on March 13, depicts the emotional struggle of a child attempting to fit into her welcoming foster family while silently agonizing over the mother she is, at least temporarily, separated from. It’s a struggle virtually anyone who works or volunteers within the child welfare system recognizes.

“What we say around here is that sometimes the mechanics are not accurate on the show, but the ‘feels’ are definitely accurate,” said Richard Heyl de Ortiz, executive director of the Adoptive and Foster Family Coalition of New York. His organization has used the child welfare themes addressed in the show as a springboard for panel discussions with social workers, adoptive parents and adoptees, among others.

“Generally speaking, children want to be with their biological families,” Mr. Heyl de Ortiz said. “Those are their people; it’s their tribe.”

During her 15 years on the bench in San Mateo County, Calif., Ms. Bresee presided over hundreds of hearings related to delinquency, dependency, guardianship and adoption. She has seen how the number of open adoptions has grown, allowing more children a permanent connection to their biological family even when reunification isn’t possible.

“I never had a kid who didn’t want to go home or at least continue to have a relationship with their parent,” Ms. Bresee said. “Even parents who had been physically or sexually abusive to them.”

Many times, including in cases involving addiction or incarceration, ongoing contact is encouraged. The need for the children to see and be comforted by their parents often outweighs any potentially negative circumstances of the visit. However, there are cases of abuse in which the court may decide that it’s not in the best interests of the child to remain in contact with the biological parents. But the child may still feel the loss, Ms. Bresee said.

“We don’t recognize how they’re grieving,” she said. “We should all think about what it would mean to lose a parent. They’re your rock. Even if the rock is a crag that’s cutting our hand, it’s still the only rock we’ve ever known.”